The contractile model for ciliary motion will be applied to the motion of invertebrate sperm flagella. The circumstances to be investigated are: normal and restrained motion, high viscosity, reactivated sperm, the starting of motion, asymmetric motion. The mechanical aspects of the signals that coordinate and initiate ciliary motion will be investigated. To be observed are the details of ciliary motion in reversal, the motions of the basal body, and the effects of microdissection of basal and cortical structures. The mechanisms by which Mg ions and Ca ions control cellular flagellar motion, will be investigated by internal localization, the application of fluorescent dyes and of ionophores. Pilot studies will be made of the action of stimulants and hormones on cellular flagellar motion.